The Internet is broken
If you are working in IT or if you computer scientist, you probably have mumbled this sentence already before yourself: "the network is broken", or more specific, "the Internet is broken".
But what is really wrong with the Internet?
Computers are not reachable by default
One of the most bizarre and weird things in the Internet is that computers cannot reach each other. You might have a question mark reading this claim, so I'll try to elaborate a bit:
While you are reading this article, checkout your IP address on your computer. Does it start with 192.168., 10. or 172.16.? It probably does and that means your computer is configured to use a private, or degraded IPv4 address. These addresses are being filtered on the Internet and are used, because your provider does not have enough proper, public IPv4 addresses.
What is the problem with degraded IP addresses?
The first problem is that these IP addresses are used multiple times. You, your neighbor, people in different cities - they all use the same IP address. So if you want to reach their computer you need to tell your computer "I want to reach that computer on 192.168.1.42", but your computer is already on the same address! How can it send to 192.168.1.42? It can't!
The second problem with these degraded IP addresses is that you cannot use them on the Internet. Because these IP addresses are private and not supposed to be seen in the Internet, they are filtered by ISPs.
You might be puzzled reading this, because you are in the Internet reading this article, aren't you?
You are not in the Internet
Practically seen, having a private IP address, you are a second class citizen of the Internet. You cannot tell anybody else "this is my IP address, just download a file from my computer". If you want to download a file from a friend, you will need to use an external service, like cloud storage.
If you want to chat with someone, you again cannot just connect to the computer or mobile phone of the person you want to connect to. Instead you will need to use another intermediary party.
This is not the Internet. The Internet is a network of networks, which allows anyone to connect anywhere.
You want to access your own NAS that is in your home? You'll again need to connect it to someone else to be able to reach it.
All those intermediate services introduce latency and cost into your daily routine. For many of us above scenario sounds like a normal thing to do. However, it is a very degraded version of the Internet that we are using.
No public IP addresses left
So why are using private IP addresses anyway? Basically your ISP, like almost all ISPs in the world does not have enough public IP addresses to give every of your device a public IP address. So instead of connecting you directly to the Internet, you are given a maximum of 1 public IPv4 address for all your devices.
However even 1 public IPv4 address per customer was too much for some ISPs. So they started repeating the NAT process, making the network more complex, slower and also putting you further away from other participants of the Internet.
The new Internet
Some of you already can guess where this article is going to and you are right: It's about IPv6. While there have been many articles written about IPv6, I think it is important to remember that the old IPv4 does not work like an Internet anymore. IPv6 with its huge amount of addresses fixes this problem for many human lives ahead. IPv6 restores direct connectivity.
If you think you don't need to care about IPv6 and you are fine with the current status, think about it this way: the Internet usage is growing. Without IPv6, the Internet is becoming slower every day. Without IPv6 you get more depending on a small amount of big companies. And this dependency is getting more and more difficult to reverse in the future.
Switching to IPv6 today
The good news is: you can switch to using IPv6 today. You can request IPv6 from your current ISP and if your ISP does not support IPv6, you can change your ISP. Even if there is no ISP with IPv6 around, you can get IPv6 via anywhere using the VIIRB using the IPv6VPN.
At the moment about 33% or one third of the Internet have already switched to IPv6, according to Google. APNIC even provides a nice map showing the IPv6 adoption on a per country and per ISP basis.
Besides making the Internet faster, more reliable and less complex with IPv6, there is one more reason to switch today: IPv6 is fun!